vmod-xcounter
Custom Counter
Author: | Shohei Tanaka(@xcir) |
---|---|
Date: | 2021-02-23 |
Version: | 65.4 |
Support Varnish Version: | 6.0.x 6.1.x 6.2.x 6.3.x 6.4.x 6.5.x |
Check Varnish Version: | see .github/workflows/test.yml |
Manual section: | 3 |
SYNOPSIS
import xcounter;
Versioning(Source)
[varnish-version].[library-version]
65.1 is v1 for Varnish6.5.x
Versioning(Package)
[VRT-version].[Source-version]
120.65.1 is 65.1 for VRT12.0
VRT Version | Varnish Version |
13.0 | Next |
12.0 | 6.5.x |
11.0 | 6.4.x |
10.0 | 6.3.x |
9.0 | 6.2.x |
8.0 | 6.1.x |
7.1 | 6.0.4~6.0.x |
7.0 | 6.0.0~6.0.3 |
DESCRIPTION
vmod_xcounter enables custom counter in Varnish.
varnishstat -f XCNT.*
For example, count to the number of requests per domain.
vcl sample:
import xcounter; sub vcl_init { new example_net = xcounter.vsc(); } sub vcl_recv { if(req.http.host == "example.net"){ example_net.incr(1); } }
varnishstat output
$ sudo varnishstat -1 -f "XCNT.*" XCNT.reload_20181118_042545_24957.example_net.val 1 . xcounter
ATTENTION
The counter is linked to the VCL.
Add new entry per new(reload) VCL.
INT elapsed()
- Description
- Get elapsed time.
Example
if(xcounter.elapsed() > 1s){...}
vsc(...)
new xvsc = vsc( ENUM {bitmap, bytes, duration, integer} format=integer, ENUM {bitmap, counter, gauge} type=counter, ENUM {info, debug, diag} level=info, STRING oneliner="xcounter", BOOL hidecold=1, BOOL hidevclname=0, STRING groupname="" )
- Description
Create a counter.
Counter name format
XCNT.boot.group.object.val ("XCNT.%s.%s%s.val", vclname, groupname, objectname)
format
Counter format.type
Counter type.level
Counter level.oneliner
Counter description.hidecold
Hide counter, if state of vcl becomes cold.hidevclname
Do not include vclname(boot,reload... etc) in counter name, if set to true.groupname
Add group name.
Example
new xcnt = xcounter.vsc();
VOID xvsc.incr(INT d, BOOL threadsafe=1)
- Description
Increment vlaue.
Negative values are ignored
Example
xcnt.incr(1);
VOID xvsc.decr(INT d, BOOL threadsafe=1)
- Description
Decrement value.
Negative values are ignored.
Example
xcnt.decr(1);
VOID xvsc.set(INT)
- Description
- Set value.
Example
xcnt.set(1024);
INT xvsc.get()
- Description
- Get current value.
Example
if(xcnt.get() > 1024){...}
INSTALLATION
Binaries for Varnish 6.0 LTS (CentOS / RedHat 7)
Provided by GetPageSpeed
yum -y install https://extras.getpagespeed.com/release-el7-latest.rpm yum-utils yum-config-manager --enable getpagespeed-extras-varnish60 yum install vmod-xcounter
More on the VMODs repository here.
Source build
For other platforms you would use compilation.
The source tree is based on autotools to configure the building, and
does also have the necessary bits in place to do functional unit tests
using the varnishtest
tool.
Building requires the Varnish header files and uses pkg-config to find the necessary paths.
Usage:
./autogen.sh ./configure
If you have installed Varnish to a non-standard directory, call
autogen.sh
and configure
with PKG_CONFIG_PATH
pointing to
the appropriate path. For instance, when varnishd configure was called
with --prefix=$PREFIX
, use
export PKG_CONFIG_PATH=${PREFIX}/lib/pkgconfig export ACLOCAL_PATH=${PREFIX}/share/aclocal
The module will inherit its prefix from Varnish, unless you specify a
different --prefix
when running the configure
script for this
module.
Make targets:
- make - builds the vmod.
- make install - installs your vmod.
- make check - runs the unit tests in
src/tests/*.vtc
. - make distcheck - run check and prepare a tarball of the vmod.
If you build a dist tarball, you don't need any of the autotools or pkg-config. You can build the module simply by running:
./configure make
Package build
This function is beta.
Usage:
./sw_vrt.sh [VRT version] debuild -us -uc
Installation directories
By default, the vmod configure
script installs the built vmod in the
directory relevant to the prefix. The vmod installation directory can be
overridden by passing the vmoddir
variable to make install
.
COMMON PROBLEMS
configure: error: Need varnish.m4 -- see README.rst
Check whether
PKG_CONFIG_PATH
andACLOCAL_PATH
were set correctly before callingautogen.sh
andconfigure
Incompatibilities with different Varnish Cache versions
Make sure you build this vmod against its correspondent Varnish Cache version. For instance, to build against Varnish Cache 4.1, this vmod must be built from branch 4.1.
Require GCC
This vmod using GCC Atomic builtins.